Drawout-style electrical circuit breakers are connected and disconnected by moving breakers thereof physically away from and towards a bus. These actions are done with a tool known in the industry as a “racking” wrench, and the processes of disconnecting and connecting breakers are collectively known in the art as “racking” breakers.
Incidents of serious and sometimes fatal injury can occur if circuit breakers on a live bus fault while being racked.
The current OSHA Standard (29CFR-1910-S-App. “A”-NFPA70E) requires that personnel wear full-body flash suits during racking procedures on energized systems. However, as operators stand within the flash boundary in a typical racking operation, they are still at considerable risk should a fault explosion occur. The need for flash suits also adds cost and inconvenience to racking operations.
An automated racking device is known in the art, in the form of a robot equipped with a racking wrench, which can be remotely operated by personnel outside the flash zone. This device is admirable in its ability to improve safety, but is relatively costly and cumbersome.